Rotary pump



eh. 28,, 950 H. J. RAND ROTARY PUMP Filed Jan. 31, 1948 am ILW/J I INVENTOR HENRY J RAN ATTORNEYJ Patented Feb. 28, 1950 ROTARY PUMP Henry .LRand,

Ohio, aaolgnor to H. J.

Bratenahl, Band Washing Machine Corp.. New York, N. Y., a corporation of Delaware Application January 31, 1948, Serial No. 5,622

6 Claims. (Cl. 103-117) This invention relates to improvements in a rotary pump of the flexible vane type.

An object of the present invention is to provide a rotary pump having flexible vanes and adapted to pump both water and air in a very eflicient manner and the improvements are particularly directed to making the pump quiet in operation and of a low torque requirement.

My improvements are shown as applied to a pump of the type disclosed and claimed in United States Patent No. 2,189,356, granted February 6, 1940, to Arthur M. Briggs, although it will be understood by those skilled in this art that my invention might be applied to other pumps of similar character.

One of the objects of the present invention is to render a pump of the Briggs type more emcient by a greater flexing of the individual vanes while at the same time reducing excessive noise by preventing the formation of closed pockets between the bent vanes and the body of the rotor.

Another object of the present invention is to remove a pump of the type wherein rotating vanes are flexed against a cam surface, consisting in the formation of the leading or trailing edge of the cam surface, or both, along lines non-parallel to the axis of the rotor whereby to decrease the noise of the pump and to greatly decrease the starting and running torque required.

Still another object of the present invention is to so slit the vanes of a rotary vane pump as to improve its operation and to decrease the noise made by the pump when rotating.

Other objects and advantages of the present invention will be apparent from the accompanying drawings and descriptions and the essential features will be set forth in the appended claims.

In the drawings,

Fig. 1 is a side elevational view of a pump equipped with my invention.

Fig. 2 is an enlarged transverse sectional view of the same taken along the line 2-4 of Fig. 1.

Fig. 3 is a fragmental sectional view taken from a position similar to Fig. 2 but showing a modified form of cam construction and the coaction of the rotating vanes therewith.

Fig. 4 is an enlarged perspective view of the pump of Fig. 3 with the rotor removed and with the top of pump housing broken away so as to more clearly show the construction of the cam.

Fig. 5 is a top plan view of the pump of Fig. 4

equipped with a rotor of the type shown in Figs. 6 an Figs. 6 and 7 are perspective and side elevational views respectively, of a rotor of the type shown in Fig. 5.

A pump of the type disclosed in the abovementioned Briggs patent is very eifective for the pumping of liquid and air or gas. Referring to Fig. 2, a rotor ill of rubber or similar material is secured to a shaft Ii which is normally supplied with suitable driving means as for instance by means of a pulley l2 for actuating the pump. The rotor has a plurality of flexible vanes l3 of rubber-like material adapted to flex when they engage a cam it which is provided at one side of the pump housing It. The liquid inlet is indicated at It and the outlet at ll. Referring to Fig. 2 the chamber it at the pump inlet is of large cross-sectional area because the vane Ila is folded back against the cam II as shown. This causes a partial vacuum in the chamber it which causes the liquid to move into the pump. As the vanes pass the conduit it the liquid is carried around between the radially extending vanes which have a very slight clearance or even slightly rub against the pump housing at this point. Where the chamber I9 is formed adjacent the outlet conduit i! the vane I3b is flexed against the cam surface it so as to reduce the cross-sectional area of the chamber i9. forces the fluid out of the pump.

In a pump of the Briggs type a bulbous end is formed at the free edge of each vane extending parallel to the axis of the rotor. I find that the Briggs pump, when the vanes are flexed as shown in Fig. 2, creates a substantially closed pocket at the place indicated at 20 in Fig. 2. In dot-dash lines at 2! I have shown the original bulbous nose of the Briggs pump. My impibvement consists in cutting off the bulbous nose; 2| along the full line indicated at 22. This opens up the pocket 20 and prevents the pounding of the pump when it is rapidly rotated.

The vanes of a pump of the Briggs type are flexed against a cam surface indicated at 4 in the above-mentioned Briggs patent. All of the elements of this cam surface are parallel to the axis of the rotor and the free edge of the vane is also parallel to this axis. It results from this construction that each vane strikes the cam surface simultaneously at all points along its free edge. This causes the Briggs pump to be noisy in operation and it requires a high starting torque. To overcome this defect, I have improved the cam shown at it in Fig. 2 of my drawings to a This This improvement consists in providing the warped surface 28 as best shown in Fig. 3. This be accomplished by removing the material to the plane surface 26 which causes the near edge of the cam it, as shown in Fig. 4, to take the formation along the dot-dash line B nonparallel to the axis of the rotor iii. If the same is done at the surface indicate at 2M in Fig. i the other edge of the cam will terminate along the line B which is also non-parallel to the axis of the rotor. With the rotor turning in the direction of the arrows of Figs. 2 and 3, the edge B of the cam it would be the leading edge and the edge B would be the trailing edge.

It results from the improvements shown in Fig. 3 and 4 that each of the vanes l3 strikes the leading edge of the cam it along the line B progressively with the edge of the vane tending to become twisted slightly as shown at its in Fig. 3 as the vane strikes the leading edge of the cam along the line B. Each vane thus slips progressively onto the cam surface with a silent action and With a less torque requirement than if the entire edge of the vane struck the cam 6, and 7. Here a rotor 25 similar to the rotor Ill is provided with a plurality of radially extendin flexible vanes 26 which are similar to the vanes It above described except that these vanes have been modified as most clearly shown in Fig. 6. Here, one or more slits 21 have been made in a radial direction along planes at right angles to the axis rotor. I flnd that a very thin razor blade will slit the rubber-like material in a desirable manner. I prefer to stagger the slits 21 in one vane with reference to the slits of the adjacent vane as clearly shown in Fig. '7. This provides a more efflcient pumping, action.

When the rotor 25 is combined with the cam It as shown in Fig. 5 a very interesting result occurs. As each of the vanes 26 encounters the leading edge B of the cam it the vane portions 26a, 26b, and 260 as indicated in Fig. 6, take a stepped position as clearly shown in' Figs. 5

and 6 as they progressively engage and pass onto the cam surface it. The lines A-A of Fig. 5 are parallel to the axis of the rotor 25. It is, therefore, obvious that the vane portions 26a, 26b, and

260 are progressively flexed as they strike the leading edge of the cam non-parallel to the axis of the rotor. Obviously, these vane portions will leave the trailing edge B of the cam l d in a, similar manner. This reduces the noise of the pump and reduces the torque required while in no way impairing its emciency.

It is obvious that the leading and trailing edge of the cam it might be formed non-parallel to the axis of the rotor in other ways than that shown at B and B. For instance, they might be of V form or curved.

What I claim is:

i. In a rotary pump of the type having a housing providing a generally cylindrical chamber. said housing provided with spaced inlet and outlet. having a cam surface on. the inside of said housing between said inlet and outlet, having a rotor concentric with said housing chamber, said rotor having a, plurality of flexible vanes projecting from the rotor body to touch said housing, said rotor body being spaced from said cam surface by an amount less than the length of said vanes and so spaced as to collapse said vanes in' extreme proximity to said rotor body upon depression by said cam surface, whereby said vanes are flexed against said cam surface adjacent said outlet to eject fluid, means for rotating said rotor, the free edges of said vanes being bulbous} and the edge of each vane flexed toward said rotor body by said cam surface being flattened, whereby to avoid formation of a substantially closed pocket between said vane and rotor body when said vane is flexed.

2. In a rotary pump of the type having a housing providing a generally cylindrical chamber, said housing provided with spaced inlet and outlet, having a cam surface on the inside of said housing between said inlet and outlet, having a rotor concentric with said housing chamber, said rotor having a plurality of flexible vanes projecting from the rotor body and perpendicularly to the axis thereof to touch said housing, said rotor body being spaced from said cam surface by an amount less than the length of said vanes, whereby said vanes are flexed against said cam surface adjacent said outlet to eject fluid, means for rotating said rotor, and said vanes being slit along lines extending radially of said rotor.

3. In a rotary pump of the type having a housing providing a generally cylindrical chamber, said housing provided with spaced inlet and outlet, having a cam surface on the inside of said housing between said inlet and outlet, having a rotor concentric with said housing chamber, said rotor having a plurality of flexible vanes projecting from the rotor body and perpendicularly to the axis thereof to touch said housing, said rotor body being spaced from said cam surface by an amount less than the length of said vanes, whereby sald vanes are flexed against said cam surface adjacent said outlet to eject fluid, means for rotating said rotor and said vanes having thin slits extending radially of said rotor, the slits of one vane being axially staggered relative to the slits of the adjacent vane.

4. In a rotary pump of the type having a, housing providing a generally cylindrical chamber, said housing provided with spaced inlet and outlet, having a cam surface on the inside of said housing between said inlet and outlet, having a rotor concentric with said housing chamber, said rotor having a plurality of flexible vanes projecting from the rotor body and perpendicul'arly to the axis thereof to touch said housing, said rotor body being spaced from said cam surface by an amount less than the length of said vanes, whereby said vanes are flexed against said .oam surface adjacent said outlet to eject fluid means for rotating said rotor, the edge of said cam first engaged by said vanes being formed along a line non-parallel to the free edges of said vanes, and said vanes being slit along lines extending radially of said rotor.

5. In a rotary pump of the type having a housing providing a generally cylindrical chamber, said housing provided with spaced inlet and outlet, having a cam surface on the inside of said housing between said inlet and outlet, having a rotor concentric with said housing chamber, said rotor having a plurality of flexible vanes projecting from the rotor body and perpendicularly to the axis thereof to touch said housing, said rotor body being spaced from said cam surface by an amount less than the length of said vanes, whereby said vanes are flexed against said cam surface adjacent said outlet to eject fluid, means for rotating said rotor, the edges of said cam flrst and last engaged by said vanes being formed along a line non-parallel to the free edges of said vane.

vanes, and said vanes-being slit along lines extendingradially of said rotor.

6. In a rotory pump of the type having a housing providing a generally cylindrical chamber, said housing provided with spaced inlet and out-' let, having a, cam surface on the inside of said housing between said inlet and outlet, having a rotor concentric with said housing chamber, said rotor having a plurality of flexible vanes projecting from the rotor body and perpendicularly to the axis thereof to touch said housing, said rotor body being spaced from said cam surface 'by an amount less than the length of said vanes,

f whereby said vanes are flexed against said cam P81111808 adjacent said outlet to eject fluid, means for rotating said rotor, the edge of said cam first engaged by said vanes being formed along, a line non-parallel to the free edges of said vanes, said vanes having thin slits extending radially of said rotor. and the slits of one vane being axially staggered relative to the slits of the adjacent HENRY J. RAND.

REFERENCES crran The following references are of record in the iile of this patent: 

